FIG. 2.

Axin1^del/del embryos died during early embryonic development. A: Southern blot analysis using 5′ probe and exon 2 probe confirmed the deletion of exon 2 of the Axin1 gene in Axin1^+/del mice. The genomic DNA was digested with BamHI and BglII. The 5′ probe detected 6.1-kb and 4.6-kb fragments for wild-type allele and flox allele, respectively. The exon 2 probe detected 6.1-kb and 2.1-kb fragments for wild-type allele and 1.3-kb and 1.6-kb fragments for flox allele. B: Western blot analysis on Axin1 in Axin1^+/del and Axin1^del/del embryos. Total protein extract from E9.5 embryos were blotted for Axin1 and β-actin (the loading control). C: Axin1^del/del mice display an embryonic lethal phenotype. E9.5 and E10.5 Axin1^del/del embryos are much smaller than their wild-type littermates (C1–C4). Axin1^del/del embryos show underdeveloped head folds (C2, white arrow) and open head folds (C4, yellow arrow). Ys, yolk sac. Bars: 0.5 mm.